Separable electrical connector



M. L. HOWELL SEPARABLE ELECTRICAL CONNECTOR Filed Sept. 24, 1938 mwa@ Dec. 19, 1939.

NITED STATES PATENT ortica 2,183,911 SEPARABLE ELECTRICAL CONNECTOR Martin Luther Howell,` Freedom, Pa.

Application September 24, 1938, Serial No. 231,599

3 Claims.

This invention relates to new and useful improvements in electrical connectors generally, although more particularly to separable connectors of the type employed in households, usually in baseboards.

` Heretofore such connecting sockets have been of two general types; one type having an open threaded socket and a cooperating threaded plug, and the other type having a socket provided with spaced recesses, generally rectangular, and a cooperating plug having spaced contact fingers registering with and insertible ,into the recesses in the socket.

The `first of these types has been the source of many accidents to human beings, especially children who are apt to insert a ngei into the socket and thereby receive a severe -if not fatal shock.

The second of these types, while considerably cessfully overcome the foregoing objections and diiliculties.

The principal object of my invention is to provide a separable electrical connector of the type stated which includes a cylindrical socket having axially spaced contact rings and a cooperating plug having contact surfaces disposed to register with the rings in the socket to thereby complete an electrical circuit through the connector.

Another object .of my invention is to provide a device of the above character in which the plug contact surfaces maintain contact with the socket contact rings regardless of relative rotative movement between the plug and socket.

Another object of the invention is to provide a socket of the nature stated in which is embodied a novel contact and spacer ring assembly.

Another object of the invention is to provide a novel connector of the character stated in which is embodied a novel arrangement of contacts and novel means for preventing short circuiting of wiring connections.

Another object of my invention is to provide a device of the above character which is simple in construction and economical to manufacture.

With these and other objects in view which will more fully appear, the nature of the invention will be more clearly understood by following the line l-,I on Figure 1.

Figure 5 is a central longitudinal sectionl of the plug. A

Figure 6 is a plan view of the plug.

Figures 7 and 8 are end elevations of the socket and plug respectively.

Referring to the drawing in detail my invention is embodied in a separable connector which includes a socket generally designated 5 and a plug generally designated 6.

The socket includes a cylindrical inner shell 'i of non-conducting material having an axial bore 8. A-longitudinal groove 9 is formed in the outer surface of the shell 'I and extends from one end thereof to a point somewhat past the mid-point.

' of the shell length where it terminates at a radial bore I0 extending in open communication with the axial bore 8. The. other end of the groove terminates in a radial groove 9a formed in the end of the shell. A longitudinal groove I'l is also formed in the outer surface of the shell disposed diametrically opposite the groove 9. The groove Il extends from the same shell end as the groove 9 to a point less than the midpoint of the shell length where it terminates at a radial bore l2 extending in open communication with the axial bore 8. 'I'he Yother end of the groovev terminates in, a radial groove IIB formed in the end of the shell.

Relatively thin annular copper bands i3 are positioned within the axial bore 8 andare disposed to cover the inner ends of the radial bores Ill, I2. Annular ber or othernon-conducting bands' M somewhatA thicker than the copper bands are also positioned within the axial bore and are positioned to each side of the copper bands i3, in abutting relation thereto, to thereby provide an inner surface to the bore having depressed areas at the copper bands and to suitably y space the copper bands. c

A contact rod I5 is secured in the groove 9 by some suitable means such as screws i6 and has one end bent inwardly into the radial bore Il) and into yielding contact with the associated copper band as at il, the other end of the strip being headed as at 8 to receive a binding post or terminal screw I9 for connection with one wire 20 of an electrical conductor 2|. A similar contact strip 22 is secured in the groove II, being secured in place by a screw 23, bent into yielding contact as at 24 with the associated copper band I3 and headed at 25 at its other end to receive the terminal element 26 for making connection with the other wire 20 of the conductor 2|.

A cover shell 21 having a hemispherical head 28 at one end thereof is telescoped over the inner shell and has its open end abutting a cover plate 29 secured to one end of the inner shell by screws 38. The cover plate is provided with a cylindrical opening 3| having a diameter substantially equal to that of the axial bore of the inner shell. The head 28 of the cover shell 21 is provided with an opening 32 through which electrical conductor 2| can be inserted.

The plug 6 includes a cylindrical body member 33 having a diameter slightly less than the axial bore 8 of the socket shell, and a two-,piece nger knob or head 34 including a removable cover 35 secured thereto by screws 36 `and having an abutment face 31 disposed at right angles to the axis thereof and opposed to the outer end of the socket. The nger knob is provided with a cavity 38 slightly greater in length than the width of the body member. The cavity is divided 'into two sections by a transversely disposed rib 39. A longitudinal groove 40 is formed in the body member 33 and extends from the abutment face 31 to a point less than the mid-point of the body member length. A similar groove 4| is disposed diametrically opposite the groove 40 but extends a considerable distance past the 'midpoint of the body member length.

A contact rod 42 having an upwardly bowed resilient end portion 43 is located within the groove 40 and is secured therein by a. terminal bolt 44 extending through the finger knob into the cavity 38. The bowed end portion of the contact extends outwardly somewhat beyond the external surface of the body member.

A similar contact 45 having a bowed resilient end portion 46 is secured by a terminal bolt 41 in the groove 4| and similarly projects from said groove.

It is to be noted that the distance from the abutment face 31 to the bowed contact portion 43 is equal to the distance from the plate 29 to the near copper band I3 of the socket, and that the distance from the abutment face to the bowed contact portion 46 is substantially equal to the distance from the plate I9 to the other band I3 in the socket.

An electrical conductor 48 is led through an aperture in the end of the finger knob into the cavity 38 and has its individual wires 49 secured respectively to the terminal bolts 44 and 41.

In use the socket 8 is secured within the baseboard in a building or the like and connected to a source of electrical power. The plug 1 is connected to any desired attachment or appliance. When it is desired to make circuit with the source of power, the plug is merely inserted into the socket, the bowed contacts 43 andA 46 coming into engagement with the copper bands I3 and thereby effecting continuity of circuit. The grooves or depressed areas formed as a result of the relation of the copper bands to the ber bands serve to hold the plug in position through engagement with the contacts. It is to be noted that it is not necessary for the plug to be in any particular relation to the socket for insertion except axial alignment, and that continuity of circuit is not effected until the plug is inserted all' the way. In order to facilitate insertion of the plug, it may be provided with arounded lead-in surface If desired, a closure plate plug can be secured y in any approved manner over the center opening in the plate 29 to close the socket when not in use, as indicated by dotted lines 5| in Fig. 2.

Thus it will be seen that I have provided a separable connector which is simple in construction, economical to manufacture, and which minimizes danger to humans through the use of widely spaced axial contacts.

It is of course to be understood that the details of structure and arrangement of parts may be variously changed and modified without departing from the spirit and scope of my invention.

I claim:

1. A separable electrical connector including a socket and a plug, said socket comprising a cylindrical shell having an axial bore extending therethrough, diametrically opposite longitudinal grooves formed in the external surface of said shell, each of said grooves having an outer end terminating in a radial slot in an end of the shell and its other end terminating in a radial aperture communicating with the shell bore, one said aperture being disposed a greater distance than mid length of the shell from said shell end and the other aperture being disposed a distance less than mid length o`f the shell from said shell end, metallic contact bands positioned within said axial bore and disposed to respectively coverv the inner ends of said radial apertures, non-conducting spacer bands positioned in said axial bore and disposed in end-abutting relation to said contact bands, the contact bands being of lesser thickness than the non-conducting bands to thereby form depressed areas within said bore, a contact rod secured within each groove, each rod having one end bent inwardly in one shell aperture into yielding contact with a contact band and its other end headed and bent into the associated radial slot, and a terminal screw cooperating with each rod head.

2. A separable electrical connector including a socket and a plug, said socket comprising a cylindrical shell having an axial bore extending therethrough, diametrically opposite longitudinal grooves formed in the external surface of said shell, each of said grooves having an outer end terminating in a radial slot in an end of the shell and its other end terminating in a radial aperture communicating with the shell bore, one said aperture being disposed a greater distance than mid length of the shell from said shell end and the other aperture being disposed a distance less than mid length of the shell from said shell end, metallic contact bands positioned within said axial bore and disposed to respectively cover the inner ends of said radial apertures, non-conducting spacer bands positioned in said axial bore and disposed in end-abutting relation to said contact bands, the contact bands being of lesser thickness than the non-conducting bands to thereby form depressed areas within said bore, a contact rod secured within each groove, each rod having one end bent inwardly in one shell aperture into yielding contact with a conta'ct band and its other end headed and bent into the associated radial slot, a terminalscrew cooperating witheach rod head, an end abutment plate secured to and extending beyond the outer surface of said shell, and a shell cover telescopically mounted on said shell and having'one end closed except for a.

wiring accommodating aperture and its other end disposed in abutting relation to said plate.

3. A separable electrical connector including a socket and a plug, said socket comprising a cylindrical shell having an axial bore Aextending therethrough, longitudinal grooves formed in spaced relation in the external surface of said shell, each of said grooves terminating at one end in a radial aperture'communicating with the shell bore, said grooves being of diierent length so as to space said apertures along the shell, metallic contact bands positioned within said axial bore and disposed to respectively cover the inner en ls of said radial apertures, non-conducting spacer bands positioned in said axial bore and disposed in end-abutting relation to said contact bands, the contact bands being of lesser thickness than the non-conducting bands to thereby form depressed areas within said bore, a contact member secured Within each groove, each contact member having one end bent inwardly in one shell aperture into yielding contact with a contact band and its other end presented at an end of the shell to form a terminal contact.

MARTIN LUTHER HOWELL. 

